I have a 4 year old OS40FX. It has had moderate use, maybe 100 flights total. Lately I notice that it has very low compression and also I am unable to get a reliable idle (the idle was preiously OK). I just took the engine apart and inspected it. Everything looked good to me except that it appears that the cylinder liner has exposed brass on the inside diameter with patches of more shiny metal. Could this be the infamous OS peeling liner? I thought OS had fixed this problem more than 4 years ago.

Those of you who have experienced with the peeling liner, what are the symptoms? What does it look like?

Thanks.
Jon

Jon:

You have been bitten by the famous OS liner shelling. And no, it was not cured four years ago, it still exists. But OS swears there never was a problem.

Even the new 46 AX series, that they proudly proclaim as Advanced Bimetallic Liner (ABL) is an ad man's way to obscure the fact that the "Bi" in "Bimetallic" still stands for brass and nickel. In words we common folk use, ABL is just another way to say ABN.

I will not buy another OS engine until they go back to chromed liners, real ABC engines. And maybe not even then, if Magnum keeps the quality that OS no longer has.

What you can do to repair yours, and get the quality OS left out, is buy the liner and piston set for the Magnum XLS 46. It fits, and it's true ABC. Also a lot less expensive than the shoddy ABN parts OS would sell you.

Before you order, though, check the rest of your OS. If any other parts are needed consider just buying a complete Magnum XLS 46. All new engine, high quality, and on sale for $70 from Hobby People.

Bill.

It looks like this....total disaster ! [X(]

This is a .61 Rf (rear pipe) pattern engine....real nice engine, with a real cheap
liner....which as you can see....took a dump. OS stated that they didn't have
any problems with this engine either, and the cost of a new piston and liner
was around $115.00. [sm=stupid.gif]

I have a stash of older FSR's, and the good old OS engines, the new ones don't
hold up well enough to warrant the price, and OS offers no help when their
engine self destructs, and the owner is left holding the bag. []

Dave.

Is there any way of telling if the cylinder is nickel-plated or chromium-plated before peeling has occurred? I have a O.S. 61RF-P waiting in line for my next project and I 'll get it chrome-plated before it self destruct if that could be the case. However, it's hard to believe O.S. would put its reputation on the line by using an unproven plating process on so many of its engines.

Thanks.

Clement

I know it is hard to believe...

But every couple of weeks someone comes in here asking about his peeled OS engine... I doubt that is a coincidence... It also means that there are hundreds or even thounsands more wrecked engines out there that don't make it into these forums...

I think Williams advice hits the nail on the head.

If enough people stop buying bad OS engines, maybe they will realise they are doing something wrong... and correct it before they go down completely...

Thanks for all the replies. I went ahead and took out the liner. It certainly is peeled! I guess maybe I got my moneys worth from this engine. I checked my log... 170 flights and about 25 hours of flying time.

Jon:

Sorry, I don't think 25 hours life from a $120 engine is my money's worth.

Contrast that to my $45 Magnum GP 25, more than twenty YEARS, not hours, and still running fine.

Admitted, I have some OS engines that old and older, but none are ABN.

I also have a 46 FX that I expect to shell at any time.

Bill.

I agree. I have a ringed Enya that must have several hundred hours of time and still is great. I will take the advice given and replace the OS with a Magnum or Thunder Tiger.

You couldn't of got better advice than what Bill gave you!

I too have sworn off the OS line until they get their "you know what" together. There are way too many other true ABC quality motors out there, and at way better prices!!

You can't go wrong with the Magnum line.

Gary

Nickel plated liners are plated all over (as can be seen in those photos). Chromed liners are only plated in the bore itself and the outside is just brass.

Thanks Downunder, I guess chromium is expensive and nickel is dirt cheap and hence the difference.

Clement

Can't remember who, but someone pointed out that chromoe plating has become increasingly problematic from a buisness standpoint due to disposal of toxic waste that is produced. Myabe harder to set up profitably in some countries as opposed to others. Not making excuses for O.S., just repeating what somebody pointed out. It'll be a pain if either of my .46 FXs peel, but meanwhile they continue to run sooooo sweet. Glad to hear that the Magnum liner will fit.

SC

Scott:

Environmental issues no doubt play a part, but Saito and Enya, both made in Japan, still use chrome plating. And I think YS does also.

With this in mind I can only assume OS went to nickel plating just because it is less expensive, and by holding the engine price up its purpose was to increase the profit margin wbile delivering a shoddy engine.

Bill.

Chief aircraft has a great replacement engine. The MDS .40 is a true chrome engine and is being sold for 49 dollars. Don't worry about the the rumors about its performance. I have broken in and run many of these engines in ARF Combos as a club trainer (in another state before I moved to CO) and was very impressed with their performance. The MDS reputation is unfounded as long as you know to tune an engine.

I have 2 OS .40 FX engines in one of my twins that seem to be ok so far (I'm replacing them soon w/ 2 MDS .58 to help cope with my 7500 altitude). I hope that they last a longer than 25 hours. I've got close to 300 hours on my MDS .68 and it runs fairly strong-only about 300 rpm shy of its max rpm when it was newer. Gotta love chrome!!!!

Could someone enlighten me please

If "peeling" means an entire piece of nickel plating coming off the cylinder wall while the engine is running, that should spell disaster but both JPMacG's and Flyboy Dave's cylinders seem to have "peeled" quite severely. On the other hand, if the nickel plating is slowly worn away, I suppose the top part of the cylinder should suffer the most coz these cylinders are tappered inside, but that isn't the case. Also, the nickel plating on the outside wall has come off too (around the exhaust port). This really puzzles me[&:]

Clement

I manage to find some cylinders for comparson.

From the left: O.S. 61RF, Picco, Rossi, steel with ringed piston.

When the 46FX peels or wears out naturally------ you can replace the piston/cylinder assembly with parts from the 46Heli engine. The heli is a ringed piston/cylinder. It's an exact fit and will run great. It's still a nickle lined cylinder, so can't attest to longevity, but mine runs absolutely awesome. It runs a few thousand RPM better now than when it was ABN and brand new. I did replace the bearings with some nice Boca bearings, but thats the extent of the hop-ups on the engine. I'm convinced that the ringed piston/cylinder runs better than the ABN. Give it a try when your engine wear out.

Thanks for all the help! Do I understand correctly that the piston and liner for the Magnum XLS 46 will fit my OS40FX (not 46FX) properly? Also, where can I purchase Magnum parts? Are parts available from Hobby People?

Jon

Jon:

On the Magnum XLS 40 and the Magnum XLS 46 all dimensions, except the cylinder bore, are the same. Other than the piston and liner, and ignoring the "40" or "46" cast into the crankcase, all the parts can be interchanged freely. In fact, other than the p/l, head, and crankcase they all have the same part numbers. I don't know if OS has the same commonality in the 40 and 46 FX engines.

Measure the outside diameter of your cylinder liner. The Magnum and 46 FXare 1.000" diameter. If your 40 FX is also 1" diameter there's no reason you should not get the XLS 46 liner and piston, get a little hop-up along with a better, less expensive, piston and liner.

The part number for the XLS 40 P/L is S40203, the XLS 46 P/L set is S46203. The wrist pin is also shown as different between the 40 and 46, I suppose it's just length since they both use the same connecting rod, so if you go for the 46 order also the 46123 wrist pin and retainer. And as a matter of course, the head gasket S46112. THis number works on both the 40 and 46 engines.

And yes, these parts are available from Hobby People, they are the inporters.

Note: The cylinder heads show different part numbers also, but one will bolt in place of the other.

Hope this helps.

Bill.

Thanks Bill. You've been very helpful. I measured the OD of the OS40FX sleeve and it is indeed 1.000"

Jon

WOW Bill.....you went WAY beyond the call of duty, and I'd like to commend you for the help you gave this young man! You did about everything but offer to do the work for him......errrrr, or did'ja? [sm=surprised.gif]

Go for the "46" P/L Jon, it'll be mo' better!

Gary

To make a comment on one of the above posts regarding lifespan. A properly broken in, fed, tuned and cared for glow engine should last about 400 hours of run time. My experience has shown me exactly that and has been verified by George Aldrich (prior to his passing). I have seen control line engines and many lapped iron engines exceed that. These numbers will hold true assuming the metalurgy of the engine is of a quality nature. I have not had any of the newer engines long enough to verify the numbers in designs that have only been available for a short time. We'll see what happens.

The plated lining is hard....when the surface fails, the whole thing goes. It's
like the shingles or tiles on a roof in a hurricane. Once the integrity of the roof is
compromised, it's a goner. []

Dave.

Mmm ... does Magnum or TT has an ABC replacement cylinder for the O.S. 61RF? Or ... where could i get my cylinder rechromed at reasonable cost?

Clement

The OS .61 RF is a long stroke engine, and as such it has a smaller piston.
I don't know if there is anything that will fit. Check the "OS-the sad demise"
thread....there's an outfit that sells replacement parts that they manufacture,
and a Guy that replates the existing parts.

There are some original parts still available, but they are over priced, and still
the same ABN junk. [sm=thumbdown.gif]

Dave.